Add Message::guild_id()

Searches the Cache for the Id of the guild that the message was posted
to - if any - and if the guild and channel data are cached.

Requires the `cache` and `method` feature flags be enabled.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/model/channel.rs b/src/model/channel.rs
index 13cf506..99fa8c5 100644
--- a/src/model/channel.rs
+++ b/src/model/channel.rs
@@ -33,6 +33,8 @@ use ::utils::builder::{CreateEmbed, CreateInvite, EditChannel};
 use ::client::CACHE;
 #[cfg(all(feature = "methods"))]
 use ::client::rest;
+#[cfg(all(feature = "cache", feature = "methods"))]
+use ::ext::cache::ChannelRef;
 
 impl Attachment {
     /// If this attachment is an image, then a tuple of the width and height
@@ -528,6 +530,21 @@ impl Message {
         }
     }
 
+    /// Retrieves the Id of the guild that the message was sent in, if sent in
+    /// one.
+    ///
+    /// Returns `None` if the channel data or guild data does not exist in the
+    /// cache.
+    #[cfg(all(feature = "cache", feature = "methods"))]
+    pub fn guild_id(&self) -> Option<GuildId> {
+        let cache = CACHE.read().unwrap();
+
+        match cache.get_channel(self.channel_id) {
+            Some(ChannelRef::Guild(channel)) => Some(channel.guild_id),
+            _ => None,
+        }
+    }
+
     /// Checks the length of a string to ensure that it is within Discord's
     /// maximum message length limit.
     ///